*{
    padding: 0;
    margin: 0;
    list-style: none;
}
body {
    background-color: #ccc;
}
.game-box {
    margin: 10px auto;
    width: 800px;
    height: 850px;
    border: solid 1px #333;
    background-color: #fff;
    position: relative;
    overflow: hidden;
}

.game-box .game-top-choice{
    padding: 5px 10px;
    width: calc(100% - 23px);
    height: 39px;
    border-bottom: solid 1px #009bf7;
}
.game-box .game-top-choice .choice-box {
    display: inline-block;
    padding: 5px 10px;
    border-right: solid 1px #009bf7;
    cursor: pointer;
    color: #333;
}
.game-box .game-top-choice div:last-child {
    border-right: none;
}
.quit {
    float: right;
    color: #ccc;
    background-color: #009bf7;
}
.game-main {
    position: relative;
    overflow: hidden;
    height: 800px;
}
.bird {
    position: absolute;
    left: 150px;
    width: 50px;
    height: 50px;
    background-color: black;
}
.topG{
    position: absolute;
    top: 0;
    width: 50px;
    background: black;
    left: 800px;
}
.bottomG{
    position: absolute;
    width: 50px;
    background: black;
    left: 800px;
}